Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description.
When a wireless device (such as user equipment (UE)) transmits physicals channels (such as Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH), or Physical Random Access Channel) or signals (such as Sounding Reference Signals (SRS)), the maximum power level at which the UE makes those transmissions is generally bounded by a configured maximum transmit power (Pcmax) value.
For UE transmissions corresponding to multiple component carriers or serving cells (e.g., c1, c2, c3) in a carrier aggregation scenario, UE transmissions corresponding to each serving cell are bounded by a respective per serving cell configured maximum transmit power value Pcmax,c (where c=c1, c2, c3), and the cumulative power of the transmissions across all the serving cells is bounded by a total configured maximum output power P_cmax. Pcmax,c used by the UE needs to be within a particular range with the higher bound typically determined by the Power class declared (Ppowerclass) by the UE and any higher layer (e.g., Radio Resource Control (RRC)) configured power limits (P_emax,c), and the lower bound based on P_powerclass, p-emax, and maximum values of any power reductions that the UE can apply.
For example, UE transmissions corresponding to serving cell c are bounded by PCMAX,c that needs be in the following range shown below.
PCMAX_L,c≤PCMAX,c≤PCMAX_H,c withPCMAX_L,c=MIN{PEMAX,c, PPowerClass−MAX(X−MPR,c))}PCMAX_H,c=MIN{PEMAX,c, PPowerClass}where                PCMAX_H,c is the higher bound on PCMAX,c         PCMAX_L,c is the lower bound on PCMAX,c         PEMAX,c is a higher layer (e.g., RRC) configured power limit        Ppowerclass is the UE power class and is a maximum UE power value that is present in specifications;        X-MPR,c is the sum of maximum values of power reductions that the UE is allowed to take        and the above values are in dB scale        
For the case where UE has transmissions corresponding to multiple component carriers or serving cells, the total configured maximum output power PCMAX1 needs to be within the following bounds:
PCMAX_L≤PCMAX≤PCMAX_H PCMAX_L=MIN{10 log10 ΣMIN[pEMAX,c, pPowerClass/(x−mpr,c)], PPowerClass}PCMAX_H=MIN{10 log10ΣpEMAX,c, PPowerClass}where                pEMAX,c is the linear value of PEMAX,c;         PPowerClass is the UE power class and is a maximum UE power value that is present in specifications;        pPowerClass is the linear value of PPowerClass;        x-mpr,c is the linear value of X-MPR,c described above for each serving cell c;        and the summation (Σ( ) ) shown above is applied across all the serving cell (e.g. c1,c2,c3) on which the UE has transmissions.        
There currently exist certain challenges. In some cases, the UE may be required to perform transmissions corresponding to different radio access technologies (RATs). For example, the UE can be scheduled such that it needs to transmit simultaneously or overlapping with a transmission corresponding to a first serving cell c1 associated with a long-term evolution (LTE) RAT and a second serving cell c2 associated with new radio (NR) RAT. A suitable mechanism for determining configured maximum transmit power value(s) that takes into account UE implementation complexity for such scenarios is needed (e.g., the UE operation on LTE RAT may not be aware of NR side transmission parameters/setting, which could result in undesirable effects).
Certain aspects of the present disclosure and their embodiments may provide solutions to these or other challenges.